Ability to move all content down from a point, create space

One of my most common annoyance is having to add a new section, title, content, etc in a webpage/app mockup that’s already completed.

To create space for that new content, I need to start by making the artboard bigger. Then select all my content under that point, and move it lower. Some background might be locked, some other content too. It’s a bit tedious. I’ll probably have to do this 2-3 times while building the content as the space needed changes.

One solution would be to have the whole artboard as a vertical Smart Layout, but that brings a bunch of other issues.

What I’d prefer is a tool, similar to an inversed crop tool maybe? I select this tool, set it as ‘vertical’, click and drag anywhere on the canvas between 2 elements, and it will start adding empty space between them. It pushes everything under that point lower, and resizes the canvas accordingly. If there is an element like a rectangle background under the click area, this one would be scaled accordingly too.

I hope it kinda make sense. I could do a little screencast to explain it better.

Thanks!